This invention concerns a lighting device which may be used to provide ambient light or for display purposes and including a light source, preferably light emitting diodes (LEDs) to produce an overall light output from the device equivalent to, if not in excess of, the light output expected from a fluorescent tube, but with considerably less electrical energy consumption and with a much more compact device overall. The invention is predicated upon the principle of injecting light into a transparent body and causing the light to be totally internally reflected therein and then diffusely reflected outwards therefrom using a diffusely reflective medium.